A process and machine for the manufacture of tires are known from the prior art, such as described in the patent EP 0 666 165 B1, wherein the arrangement of the manufacturing stations is simplified, and wherein the entirety of devices for carrying out the assembly and vulcanisation stages is concentrated on one chassis acting as a single platform intended to receive the mechanical elements of the machine.
This manufacturing process uses a rigid core which may be dismantled and which partially imposes its shape on the tire. The core is formed of plural elements which are separable from one another and which form, once assembled, a stable surface of revolution used for manufacturing a tire, from assembly where it acts as a reference surface for the application of various components, through to vulcanisation where it forms the mould of the internal portion of the tire. When it is assembled, the core can be grasped by each of the faces of its central portion, forming a rim, so as to be transferred from one station to another.
The first manufacturing stage includes assembling the elements of the core and positioning this in a station for assembling the components of the tire. The assembly stage includes depositing all the components of the tire consecutively on the core in a specified order of assembly. The whole is then transferred to a station in which the external moulding elements complement the core and is inserted into a vulcanisation chamber. Finally, after the stage of vulcanisation, the external mould and the core are removed from the tire and the elements of the core are cooled and re-assembled for the next cycle.
The transfer of the core from one station to another is ensued by carriages circulating on the chassis on which are fixed the assembly station, the vulcanisation station which is able to cure one or more tires simultaneously, the station for dismantling and re-assembling the core and the cooling station.
The highly compact nature of the machine elements, combined with extremely rapid cycle times makes it possible to have a high-performance process which is fully adapted to forming certain types of small-dimension tires.
The need to manufacture very complex or large-dimension tires is continuously growing in order to satisfy the fitting of modern vehicles whose requirements in terms of speed, strength and safety is increasing all the time. Moreover, it is difficult to respond to the evolution of market requirements by simply revising the dimensioning of the elements of the machine as described in the specification cited by way of reference.
In particular, the increase in number of components of a different kind and the increase in diameter of the cores in combination with the increase in diameter of the tires lead to a thorough modification of the machine cycles, in particular at the assembly station, which may bring about a tangible loss in productivity.